Optical Systems with Feedback

Iterative image processing using a cavity with a phase-conjugate mirror

We describe an optical image processing system with regenerative feedback that utilizes a cavity with a phase-conjugate mirror. The system's characteristics and limitations are discussed, and its application to the implementation of iterative recovery algorithms (e.g., Gerchberg algorithm) is considered and demonstrated experimentally.

Bistable optical spatial device using direct optical feedback

Analysis and implementation of a set of optically controlled optical flip-flops on the surface of a liquid-crystal spatial- light modulator (SLM) are presented. The elementary system consists of a pair of image elements on the SLM whose input and output are coupled to each other by purely optical means. The coupling is established simultaneously and independently for all pairs of elements on the SLM.